William a



(No Model.) y I W. A.. PENDRY.

VALVE. No. 282,766. Patented Ag. 7k. 1883.

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UNITED STATES PATENT EEIcE.

WILLIAM- A. PENDRY, OF DETROIT, MICHIGAN.

VALVE.

SPECIFICATION forming part of Letters Patent No. 282,766, dated August 7, 1883. Application tiled March 15, 1883. (No model.)

. To @ZZ whom it may concern.: Y

Be it known that I, WILLIAM A. PENDEY,

' of Detroitfin the county of Wayne and State sage which it controls, and having in its center a seat for a small valve attached to the spindle which/lifts the valve proper, and con-V trols a steam-passage extending through the Y,valve proper, around the valve-stem, and opening into a thin annular space between the end of the valve and the opposite side of the steam-passage controlled thereby.

A represents the shell of a globe-valve or -the dry-pipe of an engine, in which there is a common conical valve-seat, B.

C represents a valve fitting into yalve-seat B and closing in the same direction with the current of steam or water. Valve C is extended through valve-seat B, (preferably made in two parts screwed together, as shown in the drawings,) and at the further end is enlarged, C', to substantially the same size as the surface it presents to the steam when closed. This end of the valve rests in a recess, M, formed in the opposite side of the steam-passage, but does not quitetoueh the side of said passage, a thin annular space, N, being left between them. Through the center of the valve C C is cut a hole, in which lies the valve-stem D, that part of said valve-stem which iswithf` in said valve being srnaller'thani the hole in which it plays, or else made triangular, as shown at F.

Rigidly attached to valve-stem D is a small valve, H, which closes a valve-seat Acut in valve G. g ,ji

G represents a pin through valve-stem D to raise valve C when stem D is raised by engaging with shoulders O in valve C C.

E is a stuffing-box.

L represents` fair leaders for valve C, and I is an extension of stem D to guide said stem, and playing in guide K.

. Xrepresents one of the connecting-rods from the rock-shaft, usually employed to operate the throttle-valve of a locomotive. c

The operation of my invention is as follows:

-The valve,being closed, is held so firmly to its seat by the steam-pressure that great forcev is required to open it directly. When valvestem D is pressed inwardly it first opens the small valve, H, which can be 'done -without much force. Steam rushges into the hole through valve C, passing around the small part of stem D, and can only find exit into thestean-pipe by passing through the thin annular space N. This causes the steam to exert a ressure on the face of the end G of valve C, hich tends to counterbalance the steam-pressure on the other end of said valve, so that whenpin G strikes shoulder O valve C can be raised easily.

It is evident that this action .of the steam can be increased or decreased by simply increas- .ing or decreasing the proportional size ofthe end C of valve C.

What I claim as niy invention, and desire to secure by Letters Patent, is-

1. The combination of the shell A, proL vided with a valveseat, B, the-valve C, eX- tending through its seat to a point adjacent to the opposite side of the passage through the shell, and provided with a longitudinal passage, and the valve-stem extending loosely through said passage, and having a valve, II, for opening and closing the said passage, said valve H being arranged to be opened by the valve-stem prior to the latter actuating the main valve, substantially as described.

2. The combination of the shell A,.pro vided with a valve-seat, B, and a recess, M, opposite the same, the valve C, extending through the valve-seat, and having an enlarged end, C', adapted to the recess, and provided with a longitudinal passage, the valve-stem extending loosely through the longitudinal passage, and having a valve, II, for opening and closing the latter, and providedwith a pin or projection, G, for lifting the main valve after the valve II has been raised, substantially as and for the purpose described.

WVM. A. PENDItY. 

